[Bug fortran/85082] New: [8 Regression] ICE with -Ofast in vn_reference_insert_pieces, at tree-ssa-sccvn.c:2624

[gs...@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85082

            Bug ID: 85082
           Summary: [8 Regression] ICE with -Ofast in
                    vn_reference_insert_pieces, at tree-ssa-sccvn.c:2624
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gs...@t-online.de
  Target Milestone: ---

Changed before 20170618 :


$ cat z1.f90
program p
   real(4) :: a, b
   integer(4) :: n, m
   equivalence (a, n)
   a = 1024.0
   m = 8
   a = 1024.0
   b = set_exponent(a, m)
   n = 8
   a = f(a, n)
   b = set_exponent(a, m)
end


$ cat z2.f90
program p
   real(8) :: a, b
   integer(8) :: n, m
   equivalence (a, n)
   a = 1024.0
   m = 8
   a = 1024.0
   b = set_exponent(a, m)
   n = 8
   a = f(a, n)
   b = set_exponent(a, m)
end


$ gfortran-7          -c z1.f90 -Ofast
$ gfortran-8-20180325 -c z1.f90 -O3
$
$ gfortran-8-20180325 -c z1.f90 -Ofast
during GIMPLE pass: fre
z1.f90:12:0:

 end

internal compiler error: in vn_reference_insert_pieces, at
tree-ssa-sccvn.c:2624
0xd11093 vn_reference_insert_pieces(tree_node*, int, tree_node*,
vec<vn_reference_op_struct, va_heap, vl_ptr>, tree_node*, unsigned int)
        ../../gcc/tree-ssa-sccvn.c:2624
0xd11151 vn_reference_lookup_or_insert_for_pieces
        ../../gcc/tree-ssa-sccvn.c:1646
0xd12135 vn_reference_lookup_3
        ../../gcc/tree-ssa-sccvn.c:2068
0xc728aa walk_non_aliased_vuses(ao_ref*, tree_node*, void* (*)(ao_ref*,
tree_node*, unsigned int, void*), void* (*)(ao_ref*, tree_node*, void*, bool*),
tree_node* (*)(tree_node*), void*)
        ../../gcc/tree-ssa-alias.c:2801
0xd0eaa0 vn_reference_lookup(tree_node*, tree_node*, vn_lookup_kind,
vn_reference_s**, bool)
        ../../gcc/tree-ssa-sccvn.c:2517
0xd0f431 eliminate_dom_walker::before_dom_children(basic_block_def*)
        ../../gcc/tree-ssa-sccvn.c:5629
0x11dd2af dom_walker::walk(basic_block_def*)
        ../../gcc/domwalk.c:353
0xd0ac38 vn_eliminate(bitmap_head*)
        ../../gcc/tree-ssa-sccvn.c:5910
0xd16da1 execute
        ../../gcc/tree-ssa-sccvn.c:6018